I would also say try working on the lighting - in some pictures it's too bright and in others too dark - you could always fidget with this PP but it is possible to do it without PP if you experiment with the time of day you are shooting xxx

I agree with the bad lighting. You really got to pay attention to where your shooting and at what time your shooting. Try shooting later in the day closer to sundown when the sun is lower and casting good shadows and a warmer light. Its pretty hard to do nature shots hell any shots in mid day without any shade. Also, some look kind of blurry to me.

80% of the photography battle is learning how to work with light. Composition can be picked up pretty easily for most people. But learning how to work with light can take years. Even if it's explained to you, the variables vary so wildly from setting to setting that it just takes lots of experience to get it down.

For these pics, I would say 2, 3, 4 and to an extent 5 suffer from harsh mid-day sun washout. One of the things I was surprised to learn is that taking pictures on a bright sunny day yields pretty crappy results most of the time - until you learn how to work with light. Yes, you must counter the mid-day sun with either a flash or even using a big defuser and reflectors. For dog shots, a defuser and reflector probably isn't going to work, so you're going to need to use a fairly close-up shot coupled with a flash.

Example:

My son in mid-day sun with no flash.

My son a few moments later with a flash.

Note the difference? See how the colors are more vibrant not only on my son (eyes and skin) but also notice how the background pops also. The washed out look is gone.

With #1, you have the rule of thirds down but you've placed the geese on the left side of the frame. I would have placed them on the right side. It looks more natural if the open part of the shot is on the side the subject is facing. The geese appear to be walking / facing left. Therefore, you should frame it so that the geese are on the right with the open part of the frame to the left.